Abstract

There are exponential increases in the number of microbes acquired or which build resistance against various antibiotics. In this study we show that, a single strain, (Escherichia coli ATCC 8739 found in the protein database) has different β-lactamases. By investigating the Blast protein database for the existence of one of that different E. coliβ-lactamases, the result shows that this protein can be found in hundreds of different microbes with 100% identity. Multiple alignment for both of β-lactamases of four E. colistrains alone or with sixteen other sequences represent β-lactamases of the classes A, B, C and D have been generated. A Phylogenic tree for the used β-lactamases shows that the four E. coli β-lactamases clustered with those of class C. Protein models for the four E. coli β-lactamases have been built from β-lactamases 3D structure using software modeller. Further more, the purpose of this study is to investigate other resistance mechanism. A model has been built to clarify the role of biofilm in the resistance elevation which can mimic what has been happened in reality. Alginate isolated from Pseudomonas aeruginosa 9027 has been produced, purified and used. E. coli and Bacillusstearothermophilus ATCC 7953 were sensitive to Penicillin or streptomycin has been used to show the role of biofilm in resistance.

Key words:  β-Lactamase, Biofilm, antibiotics resistance and protein model.